Night latches and like spring locks



June 13, 1967 B. PENNINGS ETAL 3,325,201

NIGHT LATCHES AND LIKE SPRING LOOKS Filed Sept. 9, 1964 BY M m United States Patent 3,325,201 NIGHT LATCHES AND LIKE SPRING LOCKS Bernard Pennings, Wednesbury, and David B. Legge, Codsall, England, assignors to J. Legge & Company Limited, Willenhall, Staifordshire, England Filed Sept. 9, 1964, Ser. No. 395,163 3 Claims. (Cl. 292-169) This invention relates to latches of the kind in which a manually operable device is provided for locking the spring bolt either against withdrawal or against being shot out, or both. In rim type night latches of this kind, the manually operated device, usually referred to in the lock trade as a snib bolt, is actuated from inside and can be used to prevent the door becoming latched unintentionally as it is closed and to prevent the door, when latched from being unlatched by the use of a key from the outside, according to whether the spring bolt is retained in the fully withdrawn position or in the shot-out position. Usually the snib bolt has a simple rectilinear sliding motion in or on a straight guide and is formed or provided with a recess or small fixed knob for finger operation.

It is object of the present invention to provide a new or improved latch of the kind referred to above in which the snib bolt is of improved form and in which the mechanism for effecting operation of the snib bolt is also of improved form.

The invention will now be more fully described with reference to and by the aid of the embodiment shown in the accompanying drawings, in which:

FIG. 1 is a perspective view of a night latch with the cap side of the casing removed to expose the machanism in the case side.

FIG. 2 is an elevation of FIG. 1.

FIG. 3 is a section taken on the line 33 in FIG. 2 but with the cap side replaced.

FIG. 4 is a sectional plan of FIG. 2 but with the cap side replaced.

Referring to the drawings, is the case side and 11 is the cap side of the latch casing, 12 is the spring bolt, 13 is a torsion spring loading the bolt 12 into the latching position, and 14 is a knob-operable arcuate follower, rotationally mounted in a bearing 15 in the back wall of the case side 10, for withdrawing the bolt 12 against its spring loading. The bolt 12 has a plate lath 16 which is apertured to afford, at its rear end, a transverse bar portion 17 against the forward straight edge of which both end portions of the arcuate follower 14 bear to determine the fully shot or latching position of the bolt 12, as shown.

A switch type finger lever 18 is pivotally mounted by means of trunnions 19 in bearing recesses in the back wall of the case side 10 of the latch casing and a longer arm of said lever 18 projects through a hole in said rear wall, whilst the other shorter arm projects into a notch 20 in the back edge of a snib bolt 21 which is disposed on edge across the interior of said case side 10 in which it is guided for longitudinal and angular movements in its own plane, at right-angles to that of the lath 16 of the spring bolt, by and between flanking abutments 22 on the upper and lower walls of said case side 10, end clearances to accommodate displacement of the snib bolt 21 being provided in the pockets defined between said flanking abutments 22 and the respective walls. The snib bolt is formed as a flat stamping of shallow U-shape in elevation so that it will straddle with side clearances the narrower forward end of the bolt lath, and the notch 20 is centrally disposed in the base edge of this stamping for engagement by the inner dolly throwing arm of the lever 18, whilst the said snib bolt 21 is loaded into engagement with the back ice wall of the case side 10 by a helical compression spring 23 which operates between the cap side 11 of the latch casing and one of the end limbs of the snib bolt 21, which end limbs are somewhat shorter than the distance between the cap side 11 and back wall of the case side 10 so as to allow for the tilting or angular component of the longitudinal displacement of the snib bolt 21 from one extreme position to another under the action of the throwing arm of the dolly 18. One of the snib bolt limbs is sufiiciently long and wide however, as to engage an edge notch 24 in the bolt lath 16 or an abutment 25 thereon when the spring bolt is in one or other of its extreme positions, said engagement taking place upon appropriate operation of the lever 18 and consequently displacement of the snib bolt 21 to its retaining position.

When the bolt is in its latching position the snib bolt 21 can be engaged with the notch 24 to prevent the bolt being pushed in or being withdrawn by a keyoperated follower (not shown) from outside, whilst when the bolt is fully withdrawn, the snib bolt can be engaged with the aboutment 25 to retain the bolt in that position and prevent unintentional latching of the door.

The invention provides a safeguard against accidental locking in or out of the latching or spring bolt because the snib bolt is retained in either of its extreme positions by spring pressure which requires to be overcome by the lever 18 imparting to the snib bolt 21 motion having an angular or rocking component in addition to the sliding or longitudinal component in order to move it into the other extreme position. Moreover, the construction involved in carrying out the invention, as described with reference to a preferred embodiment shown in the drawings, is of a very simple character and easy to produce since the snib bolt 21 can be made as a plate metal stamping the lever 18, with its mounting trunnions, as a small casting, whilst the locating guides 22 which flank the ends of the snib bolt 21 in the assembled lat-ch can be produced in casting or moulding the case side 10 of the latch casing.

Having fully described our invention, what we claim and desire to secure by Letters Patent is:

1. Alatch including:

(1) a casing having guides internally thereof and formed integrally therewith,

(2) a lath having a nose at one end thereof and having at least one locking abutment thereon,

(3) spring means acting on the lath to urge the lath into a position in which the nose projects from the casing,

(4) retracting means manually operable to withdraw the lath against the action of the spring into a position in which the nose is within the casing,

(5) a snib bolt movable in said guides between a first position in which it lies in the path of said locking abutment to prevent movement of the lath and a second position in which it is clear of said path,

(6) a pivotable finger lever having an operating arm extending outside the casing and having a portion within the casing,

(7) the snib bolt being a fiat plate of U-shape in side elevation alfording a base part and two arms, the snib bolt being held in the guides for movement in a direction parallel to its base,

(8) the bolt lath being received between the arms of the snib bolt, and

(9) the base of the snib bolt including a notch within which the portions of the finger lever within the casing is arranged to engage, whereby movement of the lever serves to effect movement of the snib bolt,

(10) the arrangement being that, when the snib bolt is in its first position, one of the arms of the snib bolt lies in the path of a locking abutment on the lath and that, when the snib bolt is in its second shorter than the distance between the cap side and position, neither oi the arms lie in the path of a the case side of the latch casing to allow tilting locking abutment. movement of the snib bolt during longitudinal dis- 2. A latch as claimed in claim 1 in which: placement thereof under the action of the lever. (11) the lever for effecting movement of the snib bolt 5 is provided with trunnions, References Cited (12) the back wall of the case side of the latch cas- UNITED ST S AT T ing is provided with hearing recesses in which said 824 392 6/1906 Townsend trunmons are recelvefi and 2,279,591 4/1942 Heyer 292 153 (13) a first arm of said lever pro ects through a hole 10 2,657,946 11/1953 Erkkila 292 153 in said back wall and a second arm, shorter than said first arm, projects into the notch in the snib MARVIN A. CHAMPION, Primary Examiner.

bolt. l

3. Alatch as claimed in claim 1in which: r EDWARD i Examlfle" (14) the snib bolt includes limbs which are somewhat 10 MOSES: Amsmnt Examiner- 

1. A LATCH INCLUDING: (1) A CASING HAVING GUIDES INTERNALLY THEREOF AND FORMED INTEGRALLY THEREWITH, (2) A LATH HAVING A NOSE AT ONE END THEREOF AND HAVING AT LEAST ONE LOCKING ABUTMENT THEREON, (3) SPRING MEANS ACTING ON THE LATH TO URGE THE LATH INTO A POSITION IN WHICH THE NOSE PROJECTS FROM THE CASING, (4) RETRACTING MEANS MANUALLY OPERABLE TO WITHDRAW THE LATH AGAINST THE ACTION OF THE SPRING INTO A POSITION IN WHICH THE NOSE IS WITHIN THE CASING, (5) A SNIB BOLT MOVABLE IN SAID GUIDES BETWEEN A FIRST POSITION IN WHICH IT LIES IN THE PATH OF SAID LOCKING ABUTMENT TO PREVENT MOVEMENT OF THE LATH AND A SECOND POSITION IN WHICH IT IS CLEAR OF SAID PATH, (6) A PIVOTABLE FINGER LEVER HAVING AN OPERATING ARM EXTENDING OUTSIDE THE CASING AND HAVING A PORTION WITHIN THE CASING, (7) THE SNIB BOLT BEING A FLAT PLATE OF U-SHAPE IN SIDE ELEVATION AFFORDING A BASE PART AND TWO ARMS, THE SNIB BEING HELD IN THE GUIDES FOR MOVEMENT IN A DIRECTION PARALLEL TO ITS BASE, (8) THE BOLT LATH BEING RECEIVED BETWEEN THE ARMS OF THE SNIB BOLT, AND (9) THE BASE OF THE SNIB BOLT INCLUDING A NOTCH WITHIN WHICH THE PORTIONS OF THE FINGER LEVER WITHIN THE CASING IS ARRANGED TO ENGAGE, WHEREBY MOVEMENT OF THE LEVER SERVES TO EFFECT MOVEMENT OF THE SNIB BOLT, (10) THE ARRANGEMENT BEING THAT, WHEN THE SNIB BOLT IS IN ITS FIRST POSITION, ONE OF THE ARMS OF THE SNIB BOLT LIES IN THE PATH OF A LOCKING ABUTMENT ON THE LATH AND THAT, WHEN THE SNIB BOLT IS IN ITS SECOND POSITION, NEITHER OF THE ARMS LIE IN THE PATH OF A LOCKING ABUTMENT. 